US10336212B2ActiveUtilityA1

Torque monitoring system and method

47
Assignee: FORD GLOBAL TECH LLCPriority: Nov 27, 2013Filed: Nov 27, 2013Granted: Jul 2, 2019
Est. expiryNov 27, 2033(~7.4 yrs left)· nominal 20-yr term from priority
B60L 2260/44B60L 15/20Y02T10/7275B60L 2240/429Y02T10/72Y10S903/903Y02T90/34Y02T10/7077B60L 2240/427B60L 50/61Y02T10/643B60L 50/16H02P 21/20B60L 58/30Y02T10/7005Y02T10/6217B60L 3/12Y02T10/645B60L 2240/423Y02T90/40Y02T10/64Y02T10/70Y02T10/7072Y02T10/62
47
PatentIndex Score
0
Cited by
31
References
24
Claims

Abstract

A method according to an exemplary aspect of the present disclosure includes, among other things, controlling a vehicle using an estimated torque of an electric machine, the estimated torque based on one or more parameters associated with the electric machine that are independent from measured current feedback.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
       1. A method, comprising:
 controlling a vehicle using an estimated torque of an electric machine, the estimated torque based on one or more parameters associated with the electric machine that are independent from measured current feedback, wherein the one or more parameters include measured voltages of the electric machine. 
 
     
     
       2. The method as recited in  claim 1 , comprising the step of comparing the estimated torque to an expected torque. 
     
     
       3. The method as recited in  claim 2 , wherein the step of controlling the vehicle includes preventing operation of the vehicle if a difference between the estimated torque and the expected torque exceeds a predefined threshold. 
     
     
       4. The method as recited in  claim 2 , wherein the step of controlling the vehicle includes limiting operation of the vehicle if a difference between the estimated torque and the expected torque error exceeds a predefined threshold. 
     
     
       5. The method as recited in  claim 1 , wherein the one or more parameters include estimated voltages. 
     
     
       6. The method as recited in  claim 1 , wherein the one or more parameters include inductances. 
     
     
       7. The method as recited in  claim 1 , wherein the one or more parameters include physical flux linkages. 
     
     
       8. The method as recited in  claim 1 , wherein the one or more parameters include resistances. 
     
     
       9. The method as recited in  claim 1 , wherein the estimated torque is derived using the following equation: 
       
         
           
             
               
                 T 
                 em 
               
               = 
               
                 
                   
                     3 
                     ⁢ 
                     
                       N 
                       pp 
                     
                   
                   2 
                 
                 ⁢ 
                 
                   
                     I 
                     q 
                   
                   ⁡ 
                   
                     ( 
                     
                       
                         λ 
                         m 
                       
                       - 
                       
                         
                           ( 
                           
                             
                               L 
                               q 
                             
                             - 
                             
                               L 
                               d 
                             
                           
                           ) 
                         
                         ⁢ 
                         
                           I 
                           d 
                         
                       
                     
                     ) 
                   
                 
               
             
           
         
       
       where:
 N pp  is the number of pole-pairs, 
 I q  and I d  are the q-axis and d-axis currents, respectively, 
 λ m  is the permanent magnet flux linkage, and 
 L q  and L d  are the q-axis and d-axis inductances, respectively. 
 
     
     
       10. A method, comprising:
 controlling a vehicle using an estimated torque of an electric machine, the estimated torque derived without measuring current feedback from the electric machine. 
 
     
     
       11. The method as recited in  claim 10 , wherein the estimated torque is derived from at least one of inductance estimates, voltage estimates, resistance estimates and physical flux linkage estimates associated with the electric machine. 
     
     
       12. The method as recited in  claim 10 , comprising:
 calculating the estimated torque of the electric machine; 
 comparing the estimated torque to an expected torque; and 
 performing the controlling step in response to a difference between the estimated torque and the expected torque exceeding a predefined threshold. 
 
     
     
       13. The method as recited in  claim 12 , wherein the step of performing the controlling step includes preventing operation of the vehicle. 
     
     
       14. The method as recited in  claim 12 , wherein the step of performing the controlling step includes limiting operation of the vehicle. 
     
     
       15. A torque monitoring system, comprising:
 an electric machine; and 
 a control unit configured to estimate a torque of said electric machine without measuring current feedback from said electric machine. 
 
     
     
       16. The system as recited in  claim 15 , wherein said control unit is configured to estimate said torque based on at least one of inductance estimates, voltage estimates, resistance estimates and physical flux linkage estimates associated with said electric machine. 
     
     
       17. The system as recited in  claim 15 , comprising a variable voltage converter in communication with said control unit. 
     
     
       18. The system as recited in  claim 15 , comprising an inverter connected to said electric machine by a plurality of windings. 
     
     
       19. The system as recited in  claim 15 , wherein said control unit employs the following torque equation to derive said torque: 
       
         
           
             
               
                 T 
                 em 
               
               = 
               
                 
                   
                     3 
                     ⁢ 
                     
                       N 
                       pp 
                     
                   
                   2 
                 
                 ⁢ 
                 
                   
                     I 
                     q 
                   
                   ⁡ 
                   
                     ( 
                     
                       
                         λ 
                         m 
                       
                       - 
                       
                         
                           ( 
                           
                             
                               L 
                               q 
                             
                             - 
                             
                               L 
                               d 
                             
                           
                           ) 
                         
                         ⁢ 
                         
                           I 
                           d 
                         
                       
                     
                     ) 
                   
                 
               
             
           
         
       
       where:
 N pp  is the number of pole-pairs, 
 I q  and I d  are the q-axis and d-axis currents, respectively, 
 λ m  is the permanent magnet flux linkage, and 
 L q  and L d  are the q-axis and d-axis inductances, respectively. 
 
     
     
       20. The system as recited in  claim 15 , comprising:
 an inverter; 
 a plurality of windings extending between said inverter and said electric machine; and 
 a voltage sensor configured to measure a voltage across one or more of said plurality of windings. 
 
     
     
       21. The method as recited in  claim 1 , wherein the one or more parameters include physical resistance estimates that are based on stator temperatures of the electric machine. 
     
     
       22. The method as recited in  claim 1 , wherein the one or more parameters include physical flux linkages that are estimated from a temperature of a permanent magnet of a rotor of the electric machine. 
     
     
       23. The method as recited in  claim 1 , wherein the one or more parameters include inductance estimates mapped as a function of a q-axis current and a d-axis current. 
     
     
       24. The method as recited in  claim 1 , wherein the one or more parameters include inductances, physical flux linkages, and resistances associated with the electric machine.

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